Chipset holding back my overclock?

I know my E6600 and P5W CPU and board are starting to show there age, but, I have seen many people pull off at least 3.5 with this same combination.

For me however, 3.3 is all I can get stable. These are my settings:
FSB:367
VCORE: 1.4875 (you read right)
Memory: 918MHz 5-5-5-15 (CPUZ is giving me a 4:5 ratio. This is really wack because my memory's stock speed is 1000MHz)
Memory voltage:2.0
MCH:1.065
ICH:1.05

My question is: Is my particular board's chipset just wack or do I not know what I'm doing?

Every time I go for 3.5 this thing won't post. Also if I try to lower the vcore it won't post at 3.3. Any suggestions?